Method of hulling oats and like kinds of grain



Patented Oct. 8, 1940 UNITED STATES.

Y* ori-ice Y 2.2mm METHOD or HULLING oA'r's sorcunmvV f KIND PerEmil Hamring, Kvarnliolmen, Sweden Application .n'ne 16, 1938, Serial No. 214,141

In Sweden A111115, 1938 z barley and oats have a structure which is Lbasically similar, that is the grain kernel is covered with several integral skin layers known as bran', and

contained within two layers of separately'formed husks. The inner husks are known as the"palet and the lemma and the outerhusks are known as the glumes." Although these grains are 'simi'- larly constructedthey may bedivided' Vinto types dueto and according' to their behavior upon threshing. Most kinds of grain such as wheat and barley may be'considered as a'type because grain may be rolled, ground or used as feed for other types of live stock such as hogs and the present invention is concerned with a process for removing these inner husks, the palet and lemma, from this type of grain.

In the known process of hulling oats practised in the oat-flake mills the oats has rst been dried down to a low moisture content (about 5-6%) which has caused a shrinking of thel oat-grain kernel so that the kernel and the hull can afterwards be separated more easily from each other by mechanical means. Before hulling can take place in this process the oats must rst be sorted into 4 to 8 fractions of different grain size, each of which must be passed separately Ythrough the hulling apparatus, since the small grains would otherwise not be attacked and hulled at all, while the larger grains would be wholly or partially crushed. Y

Hitherto the hulling process has been carried out almost exclusively by means of emery stones, and every time a fraction of new grain size was to be subjected to hulling it was necessary to regulate the hulling stones correspondingly. But even the most exact regulation cannot prevent tbe crushing of a lot of grains which are very brittle -after the'rhard Moreover, on account of the irregularityof theoatgrains and the existence 'of and inner grains it is not ,possible to |carryout-thesortingoi the-grains in such -a' way thatallgrainswithfkernels or equal size are assembled in -tlievsame rfraction. Owinghereto -fandalsoson 4fof an lunavoidable abrasion ofthe 'kernelslfro'm *which the -outer part is ground 'away'.*considerable losses have :arisen in said hullingjprocess.- f

The present invention 'now relates -to a new vmilling process fb'y means of-'which said losses are 'wholly eliminated, and at the same time the working procedure' isfsimpliiled. yThe novel -teatures that areconsideredicharacteristic ofthe invention are set -:"ioith with particularity in the appended claims. "The invention itself, however, both as to-itsorganiza'tion'and 'operation will best be understoodifrom-the y:following Adescription of the hulling may be facilitated in such a degree that only a slight impact effect is required to separate `the hull from the kernel, without any treatment in scourers or the like. Moreover, this result can be obtained without a'preliminary sorting of the grains in several fractions and without injury, crushing or abrasion of the grain kernels.

The swelling of the grains according to the invention is effected by causing the grains to absorb a suilicient quantity of moisture, for instance by spraying water over the same, in which operation the grains are preferably "stirred, so 'asto obtain a uniform moistening. The quantity of water used may be such that thev grains, ifdesired, are subjected to a complete washing, whereby foreign mater (dirt, etc.) sticking to the surface of the grains orpresent in the bulk of the grain is removed, which .Ironia hygenic point of view is important. Ihe water maybe of common or increased'temperature and further it may contain chemicals suitable for such a treatment, for instance sodium bisulphite. In some cases the treatment may also be carried out by means of steam.

For every kind of grain and every type of a certain grain, for instance different kinds of oats, the

sorting-ready to be subjected to a striking action or impacts against a wall or `the like, whereby the l hulls are loosened from the kerne1,for instance a machine of centrifugal type, in whichvthe hulling may be effected in one or more stages. As by the preliminary treatment the grain has obtained a very great toughness, it will be crushed by the :impact against the wall, butA the kernel will come out of thehullnuiteintact.- Y

r. fAfter-thehullingzhas been effected in this man- .Y .nera'zthmwholegmassgisdriedzaccordingto requirement,-an'd the hullsare then separated from .the .kernels byi suction or blowing. The quantity ;=.0f;kernel5 obtainedl which has only a small vol- :zumeim comparison with .the original -volume of thereafter be easily divided into a couple of' frac- 39m-tions of diierentsgrain to facilitate the sepairaticnaont-thez'paddy tables of .unhulledgrains fzwhiclrstilh'mayf .be present. Jlfhese grains which in ithefipresent process do notv amount to more T than aboutftwoforfthree .percent, are -then .taken back to' .thewater treatment stage.

'additionfftofthe direct advantages in the .z hulling process itselfwhich areattained by the present-invention;1.not only a better recovery is ffobtaixiedbutalso.arbeizteitquality` of the product 40 subsequently produced from the oats thus treated. for instance oat-akes. The surface layer of the kernels with the valuable substances contained therein is not abraded in the hulling process. Further a completely automatic working is obtained,- for instance in the production of oat flakes, which has not been possible when using 5 the production methods hitherto used.

In the foregoing the invention hasbeen described preferably in connection with the treatment of oats, but the method according to the invention may with the same advantages also be l0 applied to other kinds of grain which on hulling behave in the same manner as oats, for instance millet. A

Having now particularly described the nature of my invention 'and the manner of its operation 15 what I claim is: A

1. In a process for removing the inner husks from threshed grain, which comprises treating the grains with moisture. thereby causing a swelling of the grains and loosening of the inner husks 20 and then subjecting theswelled grains to hulling by striking effect.

2. In a process for removing the inner husks from threshed grain, which comprises spraying water over the mass of grain, 4at the same time 25 stirring the grain to ensure a uniform moistening, thereby .swelling and toughening the grain kernels and loosening the hulls. removing water sticking to the surface ofthe grains by centrifugal action, and then subjecting the grains to hulling 30 by impacts in an apparatus of centrifugal type.

. 3. In a process for removing the inner husks from, threshed grain, which comprises moi'stening the grain, thereby causing a swelling and toughening of the grains and a loosening of the husks,` as subjecting the swelled grains to hulling" by impacts, drying the whole mass, and then separating the hulls from the kernels by means of an air stream.

PER. EMIL HAMRING. 40

' Patent Ne. 2, 217,112,

CERTIFIcATE oF CORRECTION.

' v oeteber e, 1'9 b,o. PER EMIL 1a'1tnfz1-nc.A i e It is hereby'certfed that error appeare n the-printed specification.

Y of the above numbered patent equirlng correction 'as followzs: Page l, second column, line hh., for "mater" read --mattern page- 2, first column, .line

1, orthe word combine-tions" read cond 1t1ons; line 19, after "will" insert -'net; ena that the Aeem Lettere Patent eheuld be reed with this 'correction therein' that the same may conform to the -record of thee case in the Patent Officee l t A'Sgned and sealedthia4 12th day of November, A. D. 191;,0.

Henry Van Arsdale -(Seal) Acting Commissioner of Patents. 

